Different from spherical lenses, aspherical lenses have a constant radius of curvature. The radius of curvature of aspherical lenses changes continuously from the middle to the edge with the change of the main optical axis, which can better correct spherical aberration and chromatic aberration, and thus improve the spot quality of the lens. By adjusting the conical constant and the aspherical coefficient, the lens is optimized to reduce the aberration to a large extent. Aspherical lenses are designed with a single element, helping to minimize the number of lenses in an optical system. Aspherical lenses allow optical element designers to correct erections using fewer optical elements than traditional spherical elements, as the former provides them with more aberration correction than the latter can provide using multiple surfaces.